Method for making fibrous pads or mats



Jan. 4, 1944. R. M. WILEY METHOD FOR MAKING FIBROUS PAD OR MAT Filed-Oct. 24, 1941 INVENTOR. law, M. 4 M7 AU'OLA/EVJ 3%.. 3.3.3.3. I. a u Q.. f... 44 Y B Patented Jan. 4,

F i C E METHOD FOR MAKING FIBROUS PADS on MATS Ralph M/Wlley, Midland, Mlch., assignor to The Dow Chemical Company, Midland, Mich, a corporation of Michigan Application October 24, 1941, SerialNo. 416,343

1 Claim. (Ol. 28-72) This invention relates to a method of making pads, mats, bats, or like aggregates oi fibrous material andto the product thereby obtained.

Numerous uses are known for mats, or pads, composed of crossed filaments. Among such uses-areas filters, as insulation, or as padding for upholstering, and the like. whereby such mats have been produced in the past are cumbersome and require far too much manual operation.

It is accordingly an object of the present invention to provide such articles, and a simple method whereby they may be made. It is a particular object to provide a method whereby mats, orpads of fibrous material, may be prepared in a continuous manner from a yarn or filament of the desired composition.

In the accompanying drawing, Fig. 1 illustrates a mat or pad, made according to the invention,belng stripped from the spool whereon 'it was made; and Fig. 2 is a plan view taken .along line 2-2 oi Fig. 1.

According to the present invention a continuous yarn, thread, string, or filament, is wound on to a bobbin,-or spool, of any desired size, employing a higher ratio of traverse speed,

to winding speed than in most commercial spooling practice. Alternatively, several filaments may be wound on to a single spool at once. The

winding iscontinued until the desired thickness of yarn has been built up on the bobbin, whereupon the winding is discontinued and the accumulated load is cut from the, bobbin by a single cut extending from one end of the bobbin to the other, either parallel to the axis or helical with respect to the axis..= ,There is thus produced by asurprisingly simple operation a pad or'mat of high uniformity which is superior to pads of the same material produced by the heretofore known methods.

During the winding operation above referred to, it is desirable to employ such a ratio of traverse speed to winding speed that successive layers of the yarn, or filament, lie at an angle a greater than 5 with respect to one another. During the fbustomary spooling of thread, for example, this angle is of thy-order of 2 to 3 or less. If Jth'e thread were Ii-be cut from an ordinary spool, the angle at which successive layers cross one another would be found to be toosmall to give the mat form and lasting shape. For thepresent purposes it is preferred that the angle at which successive threads cross one anothershould be from about 15 to 60 or higher.

The following'example illustrates the practice of the invention.

A tightly twisted yarn made of 18 fine filamentsof a co-polymer of 90% vinylidene chloride and vinyl chloride was wound continuously on to a cylindrical bobbin 3.5 inches in The methods about 20 grams.

diameter and 6 inches long. The traverse arm was adjusted to make approximately one complete cycle for each 4 revolutions of the bobbin. The angle a at which successive layers crossed, varied from 32 to 48. The bobbin was driven at a rate of about 1200 R. P. M. The tension on the yarn during winding was maintained at The bobbin was thus loaded at a rate of about 1200 to 1400 feet. per minute, and after 10 minutes operation, a load about inch thick had been built up on the bobbin. Winding was discontinued, the bobbin removed from the machine, and the accumulated yarn yarn form, and materials of the type whose production is described may be made of cotton. silk, wool, synth ic fibers of all kinds, or from glass filaments from the spool 11 which it wasfimade. by a single cut vertical to the dii'fiflohpf winding, or parallel to the axis of rotation of the spool. It is to be understood that this is but one embodiment of the invention, as other sizes and shapes oi mats may be obtained by cutting the load from the spool in other manners. Thus, if a helical cut is made from one end of the bobbin or spool to the other, the shape of the mat can be varied widely, depending on the pitch of the helix.

The invention is not limited to small bobbins or spools of the sizes usually brought to mind by those terms, but may be applied to winding at sucha ratio of traverse to winding speeds as to cause successive layers oi the cordage to cross a one another at an angle between about 15 andabout 60, and, when the desired thickness has been built on the spool, cutting through the load from one end to the other of the spool, and removing the so-i'ormed mat from the spool.

RALPH M. WILEY. 

